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Thursday, October 11, 2007

Nobel For Catalyst Studies

Nobel prize for chemist who shed new light on ozone layer,

A German scientist whose work led to a profound understanding of the vanishing ozone layer, clean car exhausts and rusting iron celebrates his 71st birthday today as the latest Nobel prize winner in the field of chemistry.

Gerhardt Ertl, professor emeritus at the Fritz-Haber Institute in Berlin, was awarded the most prestigious honour in science, as well as a cheque for 10m Swedish kronor (£757,000), for his meticulous studies on the reactions between chemicals and solid surfaces.

His work laid the foundations for the field of research known as surface chemistry, which describes how atoms and molecules behave when they come into contact with pure surfaces.

Speaking to reporters, Professor Ertl said: "It is the best birthday present ... I was really speechless."

His studies led to breakthroughs in the development of catalysts which have become invaluable across industry. He described how carbon monoxide could be stripped from vehicle exhausts by fitting platinum catalytic converters, and how vital reactions that destroy atmospheric ozone took place on the surfaces of tiny ice crystals floating in the stratosphere.

"Gerhard Ertl was one of the first to see the potential of these new techniques. Step by step he has created a methodology for surface chemistry by demonstrating how different experimental procedures can be used to provide a complete picture of a surface reaction," the Royal Swedish Academy of Sciences reported.

The scientist first studied the behaviour of hydrogen, including how the element was produced from the electrolysis of water, and how fuel cells could convert hydrogen into electricity. Later he worked on the Haber-Bosch process, a method which uses an iron catalyst to extract nitrogen from the air, and which has revolutionised agriculture with the advent of manufactured fertilisers.

This year's prize is unusual in rewarding just one researcher, and the exclusion of others who contributed is controversial. "There have been many key players in this area, including the government's chief scientific adviser, David King, and the great American surface chemist Gabor Somorja," said Andrea Sella, a chemist at University College London.

Catherine Hunt, president of the American Chemical Society, joined others in praise of Prof Ertl. "I am delighted the prize recognizes a field of chemistry that often receives little public attention, yet has transformed lives in so many ways

German scientist Gerhard Ertl got the birthday present of his dreams yesterday: the Nobel Prize in chemistry.

Ertl, who turned 71 yesterday, won the prestigious $1.5 million award for showing in unprecedented detail how molecules of gas behave when they land on solid surfaces -- an esoteric specialty that has generated such practical benefits as cleaner-running cars, corrosion-proof metals, better computer chips and more fertile fields.

"It is the best birthday present that you can give somebody," Ertl said during a teleconference soon after he got the coveted call from Stockholm. "I was really speechless."

He meant that literally, he said later in a telephone interview. The Royal Swedish Academy of Sciences alerted him to the news in a call to his office at 11:30 in the morning and emphasized that he must not tell anyone for the next 25 minutes.

Ertl said he took that seriously and just sat in silence at his desk, not even calling his wife.

Asked if that was difficult, he averred that it was not. "It was time to digest it," he said.

That is the kind of discipline that no doubt helped Ertl succeed in the very challenging realm of chemistry in which he did his seminal experiments, experts said. Working first in Munich and later at the Fritz-Haber-Institut der Max-Planck-Gesellschaft in Berlin, Ertl spent years exploring in painstaking detail the microscopic nooks and crannies between atoms on the surfaces of various materials and figuring out what happens when gas molecules nestle into those spaces.

"It is very exacting work," said Katie Hunt, president of the Washington-based American Chemical Society, the world's largest organization of chemists. "But if we're trying to make better and greener materials by design, having this understanding at atomic and molecular levels is crucial."

Even seemingly inert surfaces, it turns out, such as the shiny veneer of a platinum pendant, can trigger surprisingly dynamic processes with surrounding gases. Electromagnetic forces in the metal can sunder the bonds that hold gas atoms together and then help those newly liberated atoms form new bonds with other atoms.

Such recombinations are the "reactions" that chemistry is all about. And Ertl's clarification of the rules of surface chemistry has allowed scientists to develop better catalysts -- materials, often metals, that help drive chemical reactions that would not otherwise occur.

For example, the surfaces inside catalytic converters grab molecules of carbon monoxide in auto exhaust and perform a shotgun marriage between them and oxygen atoms to create nontoxic carbon dioxide. Like all true catalysts, they do it endlessly, never getting used up in the process.

Similarly, scientists have harnessed Ertl's understanding of surface chemistry to more efficiently combine molecules of atmospheric nitrogen and hydrogen to make ammonia, the crucial ingredient in fertilizer, without which the world would be a far hungrier place.

In other cases, insights into surface chemistry have allowed scientists to block unwanted reactions. Some metal alloys, for example, have been designed to block the chemical reactions with air that would otherwise tarnish or corrode their surfaces.

In many of his experiments, Ertl had to measure the movements and fates of molecules on surfaces under extreme vacuum conditions so stray atoms drifting about in the air would not interfere. In a statement, the Nobel committee drew special attention to those experiments, which it said were "carried out with the greatest elegance."

Bruce E. Bursten, dean of the college of arts and sciences at the University of Tennessee and president-elect of the American Chemical Society, said Ertl's work, though largely unknown outside the halls of chemistry, has had a "huge impact" on people's lives and will continue to do so in the future.

Many chemical reactions that could help clean the environment or make new materials are impractical because they require massive inputs of energy, Bursten said. But an understanding of surface chemistry is allowing the creation of catalysts that "completely change the energetics of these reactions."